Zhang Aihua did what he could to appease the outraged mob that burst into his private party, shocked as they were to witness tables strewn with rare Yangtze river fish and imported wine. He knelt on a table, picked up a loudhailer, and begged for forgiveness.

As the Communist party boss of an industrial zone in Taizhou City, in the south-east of Jiangsu province, Zhang probably knew that this revelation of official profligacy would cost him his job. "I was wrong tonight. Please forgive me. I'll do anything if you let me go," he pleaded, according to state media.

But his pleas went unheeded. When Zhang was fired on Monday, he became the latest victim of president Xi Jinping's frugality and anti-corruption drive – an effort fuelled in no small part by an exasperated public set on exposing the country's extreme wealth gap with mobile phone cameras and microblogs.

Lavish party food.

"I was outside and saw a lot of people, so rushed up to see what the commotion was," said Jia Hongwei, a web forum administrator in Taizhou who captured the video at the industrial park's "entertainment centre" where Zhang was hosting at least 20 colleagues and investors around three well-stocked tables.

Jia's video shows a rambunctious flow of people cascading through narrow hallways and blowing past a smattering of helpless police officers in white safety helmets. The camera hones in on plates of mostly-eaten fish – poisonous pufferfish, long-tailed anchovy and largehead hairtail, according to onlookers – as well as top-shelf bottles of Chinese rice liquor and Australian Yellowtail wine.

More lavish party food.

Jia said that locals would often witness a steady flow of luxury cars streaming in and out of the complex, alerting them to the extravagance within. They learned of Zhang's banquet from an unidentified whistleblower. "Every room in the centre had a banquet, and each banquet included abalone and other expensive dishes," Jia said.

Jia stopped recording when he left at about 8pm. Yet three hours later, he was sent a photo of Zhang kneeling on the table, face contorted in distress, a loudhailer in his right hand. He posted both the photo and video online that night, and they quickly gained traction on Sina Weibo, China's most popular microblogging service. Taizhou officials began investigating Zhang over the weekend.

Zhang paid for most of the meal, which cost more than £700, state media cited an unnamed whistleblower as saying – well over the spending limit on official banquets imposed by central authorities last year.

Since Xi launched his anti-corruption drive in November, scores of officials have been sacked for malfeasance, sales of luxury goods have plummeted nationwide and high-end restaurants have reported dismal returns. Yet some analysts say that the drive has simply pushed lavish official banquets and venal gift-giving underground.

Steve Tsang, an expert on Chinese politics at the University of Nottingham, said that the central government may only tolerate the breed of citizen journalism that took down Zhang as long as it dovetails with the party's priorities. "I think if and when they are seen as crossing a line, and are focused on challenging the party, or party rule, that would be a different matter," he said. "I think the clampdown would be quite tight."